Docsity
Docsity

Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity


Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan


Guidelines and tips
Guidelines and tips

Plant Biotechnology - General Botany - Lecture Slides, Slides of Botany and Agronomy

These are the lecture slides of Botany. Key important points are: Plant Biotechnology, Bits and Bobs, Humankind, Important Difference, Controlled Manner, Fertilizers, Increasing Crop Yields, Algal Blooms, Death of Fish, Occurrences

Typology: Slides

2012/2013

Uploaded on 01/24/2013

anasuya
anasuya 🇮🇳

4

(9)

86 documents

1 / 63

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
Plant Biotechnology and GMOs
Chapter 14
(Plus other bits and bobs)
Docsity.com
pf3
pf4
pf5
pf8
pf9
pfa
pfd
pfe
pff
pf12
pf13
pf14
pf15
pf16
pf17
pf18
pf19
pf1a
pf1b
pf1c
pf1d
pf1e
pf1f
pf20
pf21
pf22
pf23
pf24
pf25
pf26
pf27
pf28
pf29
pf2a
pf2b
pf2c
pf2d
pf2e
pf2f
pf30
pf31
pf32
pf33
pf34
pf35
pf36
pf37
pf38
pf39
pf3a
pf3b
pf3c
pf3d
pf3e
pf3f

Partial preview of the text

Download Plant Biotechnology - General Botany - Lecture Slides and more Slides Botany and Agronomy in PDF only on Docsity!

Plant Biotechnology and GMOs

Chapter 14

(Plus other bits and bobs)

Plant Biotechnology

  • “For centuries, humankind has made improvements to crop

plants through selective breeding and hybridization — the

controlled pollination of plants.

  • Plant biotechnology is an extension of this traditional plant

breeding with one very important difference —

  • plant biotechnology allows for the transfer of a greater variety of genetic information in a more precise, controlled manner.”

Figure 11.

Increasing crop yields

  • Algal blooms - a relatively rapid increase in the population of (usually) phytoplankton algae in an aquatic system.
  • Causes the death of fish and disruption to the whole ecosystem of the lake.
  • International regulations has led to a reduction in the occurrences of these blooms.

Figure 11.

Chemical pest control

  • Each year, 30% of crops are lost to insects and other crop pests.
  • The insects leave larva, which damage the plants further.
  • Fungi damage or kill a further 25% of crop plants each year.
  • Any substance that kills organisms that we consider undesirable are known as a pesticide.
  • An ideal pesticide would:-
    • Kill only the target species
    • Have no effect on the non- target species
    • Avoid the development of resistance
    • Breakdown to harmless compounds after a short time Docsity.com

Figure 11.

Chemical pest control

  • DDT persists in the food chain.
  • It concentrates in fish and fish- eating birds.
  • Interfere with calcium metabolism, causing a thinning in the eggs laid by the birds – break before incubation is finished – decrease in population.
  • Although DDT is now banned, it is still used in some parts of the world.

Plant Biotechnology

• The use of living cells to make products such as

pharmaceuticals, foods, and beverages

• The use of organisms such as bacteria to protect

the environment

• The use of DNA science for the production of

products, diagnostics, and research

Why would we want to modify an

organism?

  • Better crop yield, especially under harsh conditions.
  • Herbicide or disease resistance
  • Nutrition or pharmaceuticals, vaccine delivery
  • “In 2010, approximately 89% of soy and 69% of corn

grown in the U.S. were grown from Roundup Ready®

seed.”

http://www.oercommons.org/courses/detecting-genetically-modified-food-by-pcr/

Roundup Ready Gene

  • The glyphosate resistance gene protects food plants against

the broad-spectrum herbicide Glyphosate - N-

(phosphonomethyl) glycine [Roundup®], which efficiently

kills invasive weeds in the field.

  • The major advantages of the "Roundup Ready®” system

include better weed control, reduction of crop injury,

higher yield, and lower environmental impact than

traditional weed control systems.

  • Notably, fields treated with Roundup® require less tilling;

this preserves soil fertility by lessening soil run-off and

oxidation.”

Glyphosate - N-(phosphonomethyl) glycine

  • It does this by inhibiting the enzyme 5- enolpyruvylshikimate-3-phosphate synthase (EPSPS), which catalyzes the reaction of shikimate-3-phosphate (S3P) and phosphoenol pyruvate to form 5- enolpyruvyl-shikimate-3-phosphate (ESP).
  • ESP subsequently dephosphorylated to chorismate , an essential precursor in plants for these aromatic amino acids.

Glyphosate

Glycine

Roundup Ready Gene

  • Glyphosate functions by occupying the binding site of the phosphoenol pyruvate , mimicking an intermediate state of the enzyme substrates complex.
  • The "Roundup Ready®” system introduces a stable gene alteration which prevents Glyphosate binding and allowing the formation of the essential aromatic amino acids

Environmental degradation

  • When glyphosate comes into contact with the soil, it can be rapidly bound to soil particles and be inactivated.
  • Unbound glyphosate can be degraded by bacteria.
    • However, glyphosate has been shown to increase the infection rate of wheat by fusarium head blight in fields that have been treated with glyphosate.
  • In soils, half-lives vary from as little as 3 days at a site in Texas to 141 days at a site in Iowa.
  • In addition, the glyphosate metabolite amino methyl phosphonic acid has been shown to persist up to 2 years in Swedish forest soils.
  • Glyphosate absorption varies depending on the kind of soil.

Insect Resistance

  • B. thuringiensis (commonly known as 'Bt') is an insecticidal bacterium, marketed worldwide for control of many important plant pests - mainly caterpillars of the Lepidoptera (butterflies and moths) but also mosquito larvae, and simuliid blackflies that vector river blindness in Africa.
  • Bt products represent about 1% of the total ‘agrochemical’ market (fungicides, herbicides and insecticides)

Genetically modified crops

• Need to build in a:

• Promoter

• Stop signal

PROMOTER INTRON CODING SEQUENCE poly A signal

ON/OFF Switch Makes Protein stop sign

Genetically modified crops

  • So to modify a plant :
  • Need to know the DNA sequence of the gene of interest
  • Need to put an easily identifiable maker gene near or next to the gene of interest
  • Have to insert both of these into the plant nuclear genome
  • Good screen process to find successful insertion